Load handling mechanism in a lift truck



Feb. 7, 1967 J. J. EAVES 3,302,809

LOAD HANDLING MECHANISM IN A LIFT TRUCK Filed NOV. 13, 1964 INVENTOR.

JAMES J. EA VES BY yoh m flwfiz United States Patent 3,302,809 LOAD HANDLING MEfIHANlSM lb] A LEFT TRUCK James .l. Eaves, Louisville, Miss, assignor to Taylor Machine Works, Louisville, Miss. Filed Nov. 13, 1964, Ser. No. 411,055 1 Claim. (Cl. fi l-65 This invention relates generally to the loading handling mechanism in a lift truck and relates particularly to such a. mechanism mounted on the front of the lift truck for handling or manipulating saw logs, pulpwood, lumber or the like.

Saw logs or pulpwood are generally brought to the lumber mill or paper mill and deposited on a log yard to await processing. It is not unusual for the logs to be brought and deposited or piled on the log yard in a helter-skelter way. It is often desirable in processing the logs to sort out those that are of a certain size or character and to process such sorted ones together.

The contemporary fork-lift truck is perhaps the vehicle most often employed in sorting and manipulating the logs to be processed. The contemporary fork-lift truck functions very well for this work; however, certain shortcomings of such trucks have become apparent, and some of these are mentioned below.

In selecting a log or certain logs from a log pile, a considerable problem occurs because the second, third or even fourth log from the lift truck will be a species or have characteristics not desirable to be taken to the same place as the main portion of logs. Therefore, the operator has to move the logs between the machine and the undesirable log to another place or take them on to the log ramp, which means the machine make a trip for one or two (less than full load) logs thereby decreasing the emciency of the machine. Then, after the machine moves the one or two desirable logs, the operator comes back and takes the undesirable species to its proper location. Then, after this is done, the operator can thrust the forks under the log pile and get a full load of the desirable logs for the ramp.

With the present invention, the operator can work across the few desirable logs to the undesirable species, as shown in FIG. 1, and move these to their proper location, and then come back and thrust his forks under the pile and get a full fork load of desirable logs to be taken to the ramp.

From this it can be seen that moving the partial load (low efficiency) to the log ramp would be eliminated, and each trip to the log ramp would be a full load.

The other problem encountered with the contemporary fork-lift truck is the expulsion of the load of logs. The normal mast tilt is approximately 12-14 degrees outward, and it is unpractical to increase this much more since the lift truck capacity is reduced greatly as the center of gravity of the heavy mast moves out from the axle, which occurs when tilting the mast. Therefore, with only approximately 14 degrees fork tilt from tilting the mast when a log with a flat side is encountered, or if the fork happens to pick up a little dirt when loading the logs which forms a sort of Wedge, then the log will not fall off the fork as desired. Then it is necessary to rock the machine and shake the mast with the tilt cylinders to try to expel the logs. This problem is further ag gravated by the fact that bark usually builds up around the log ramp and raises the drive tires (fork end of the machine) thereby reducing the tilt angle.

The expulsion of the logs is no problem at all with the present invention since a high fork angle can be accomplished with no change of mast angle. Actually, it is common practice to tip the forks to their extreme position while approaching the log storage area or log deck and to open the clamp when the machine is in the 'ice correct position. When operating like this, it is only necessary to open the log clamp a small amount, and the logs will all spill out. Actually, by the time the operator can reverse the machine, the logs are expelled.

The present invention is directed towards overcoming such problems as above-mentioned, and one of its principal objects is to provide load handling mechanism in a fork-lift truck for lessening considerably the time and effort needed in handling or manipulating saw logs, pulpwood, lumber or the like.

A further object is to provide, in such mechanism, means whereby the operator of a lift truck may readily load a log or logs onto the forks of the truck without having to dismount from the truck seat.

A further object is to provide, in such mechanism, means whereby the operator may readily load the truck forks without the necessity of having other workmen on the ground for this task.

A further object is to provide, in such mechanism, means whereby the operator of the truck may readily unload the lift forks by operating the controls of the mechanism, without the need for other workmen on the ground.

A further object is to provide, in such mechanism, means whereby the operator of the truck may readily sort out or select desired logs from. a log pile.

A further object is to provide, in such mechanism, means whereby the operator may accurately place the logs or the like as they are unloaded from the truck.

A further object is to provide, in such mechanism, means suitable for handling either logs or lumber.

A further object is to provide, in such mechanism, means for readily stacking lumber in straight-sided stacks.

A further object is to provide such mechanism that is readily mountable on a typical fork-lift truck chassis.

A further object is generally to improve the design and construction of load handling mechanism in lift trucks.

The means by which the foregoing and other objects of the present invention are accomplished and the manner of their accomplishment will be readily understood from the following specification upon reference to the accompanying drawings, in which:

FIG. 1 is an environmental view showing the mechanism of the present invention in side elevation and in a lowered and log engaging disposition, and showing the lift truck chassis fragmentarily.

FIG. 2 is a view similar to FIG. 1 showing the mechanism of the present invention in a raised disposition.

FIG. 3 is a transverse sectional view taken as on the line lH-III of FIG. 2.

FIG. 4 is a transverse sectional view taken as on the line IV-IV of FIG. 2.

Referring now to the drawings in which the various parts are indicated by numerals, the mechanism of the present invention is indicated by the numeral 11, and the lift truck chassis by the numeral 13.

The lift truck chassis 13 is typical and includes the usual front and rear wheel and axle assemblies (front shown), an engine and drive train means, a body 15, and operator accommodating and vehicle control means, indicated by numeral 17.

Mechanism 11 includes principally an upright mast structure 19, a carriage Zl, a base member 23, a pair of leg members 25, and a pair of arm members 27.

Mast stmcture 19 is of typical construction and includes substantially a pair of opposed inwardly facing channel frame members 29 spaced apart and fixedly joined. Mast structure 19 is disposed uprightly and is pivotally secured respectively at the lower end portion of each of frame members 29 to truck chassis body 115. A pair of pivot assemblies, respectively having axially aligned pivot pins 31, pivotally support mast structure 19 from truck chassis 13 Carriage 21 is movably supported from mast structure 19 and is vertically positionable therealong. Carriage 21 is typically roller-mounted from mast structure 19 with an upper pair of rollers 33 and a lower pair of rollers 35, as best seen in FIG. 3. Rollers 33, 35 are attached respectively to frame 37 of carriage 21, which frame includes principally four members arranged in substantially square configuration. Frame 37 includes a pair of spaced and parallel vertical members 39 and a pair of spaced and parallel horizontal members 4-1. Vertical frame members 39 are of plate material and are substantially quadrilateral in shape. Horizontal members 41 are of square-sectioned bar material and are perpendicularly attached respectively to the upper and lower portions of vertical members 39. Carriage rollers 33, 35 are journaled respectively to the upper and lower rearward portions of each of vertical members 39 on stub shafts 42. The two rollers of each upper and lower pair of rollers 33, 35 are opposingly journaled respectively from vertical members 39 and rollingly engage respectively the inside channel surfaces of mast structure frame members 29.

Base member 23 preferably includes four vertically disposed members 43 and two horizontally disposed members 45 securely joined in substantially square configuration. Vertically disposed members 43 are alike, and each is of plate material elongatingly formed and having respectively upper and lower portions. Horizontally disposed members 45 include an upper and lower member and are perpendicularly fixedly joined respectively to the upper and lower portions of vertically disposed members 43.

Base member 23 is pivotally mounted at the lower portion thereof from the lower portion of carriage 21 by a pair of pivot assemblies 47. The pivot assemblies are each mounted respectively from the end portions of lower horizontal member 41 of carriage 21 and from the longitudinally spaced portions of lower horizontal member 45 of base member 23. Pivot assemblies 47 include respectively pivot pins 49 and suitable bracket means fixedly secured respectively to lower horizontal members 4-1, 4-5 of carriage 21 and base member 23.

The pair of L-shaped leg members 25 are securely mounted from base member 23. Leg members 25' are of typical lift fork configuration and mounting, and each includes a vertically disposed proximal portion 51 and a horizontally disposed distal portion 53. Members 25 are disposed respectively between paired members 43 at the proximal portions thereof, with the distal portions extending outwardly from base member 23. A pair of mounting pins 55, extending respectively through apertures in leg members 25 and members 4-3, securely mount leg members 25 from base member 23.

The pair of arm members 27 are respectively pivotally secured from the upper portion of base member 23 and extend forwardly therefrom. Arm members 27 are of arcuate configuration and hollow box-sectioned construction. The proximal end 57 of each of arm members 27 is disposed between the upper portions of each pair of vertical members 43. Aligned apertures are provided in paired members 43 and through the proximal end portions 57 of arm members 27, and pivot pins 59, extending through said apertures, pivotally mount the arm members from base member 23. A cross-member 6t? rigidly interconnects arm members 27 at the distal ends thereof (see FIG. 4). Arm members 27 are thus joined and pivotally move together. Cross-member 61 is V or wedge-shaped in cross-section and as viewed from the side, as in FIGS. 1 and 2. Thus, member 60 narrows downwardly from the ends of arm members 27 to a narrow distal tip or edge 61, and also the member is angled inwardly as at 62 towards edge 61 from the opposite side edges thereof so that wedge-like means is provided to aid n various operations, such as separating the logs, wedging therebetween, etc. The pivot axis of arm members l 27, as is the pivot axis of base member 23, substantially is parallel with the pivot axis of mast structure 13*, and transverse of the vehicle so that the mechanism is operable fore and aft or longitudinally relative to chassis 13.

Individual actuating means are provided for operatively moving selectively mast structure 19, carriage 21, base member 23, and the pair of arm members 27. Hydraulically operable piston-cylinder assemblies provide the means for selectively moving the several components of the mechanism. Such piston-cylinder assemblies are well-known hydraulic power means in lift trucks. Typically, such means includes a source of pressured hydraulic fluid carried in the truck chassis, supply lines for carrying the hydraulic fluid to and from the respective piston-cylinder assemblies, and manually operable control valve means interposed in the supply lines for controlling the passage of fluid and the action of the respective cylinders. For purposes of clarity and simplification, the above wellknown elements are not shown in the drawings, nor will they be described in detail in the specification; it, of course, being understood that the power means for the piston-cylinder assemblies of mechanism 11 and truck chassis 13 include such elements.

The individual actuating means and the piston-cylinder assemblies for the several components of mechanism 11 preferably include the following: A pair of cylinder assemblies 63 are secured to and extend respectively between upper portions of each pair of vertical members 43 and the upper intermediate portions of the pair of arm members 27. Cylinder base and rod pins 64, 65, extend ing respectively through apertures in paired vertical members 43 and through apertured brackets 67, which are secured respectively to arm members 27, pivotally secure the cylinders. Actuating cylinder assemblies 63 pivotally move the distal ends of the pair of arm members 27 toward and away from the pair of leg members 25. Another pair of cylinder assemblies 69 are pivotally secured to and extend between upper horizontal member 41 of carriage frame 37 and the intermediate portion of base member 23. Cylinder base and rod pins 71, 73, extending respectively through apertured brackets '75, 77, securely pivotally mount the cylinder assemblies. Brackets 75, mounting the base ends of the respective cylinder assemblies 69, respectively extend upwardly and rearwardly from the end portions of upper member 41 of carriage frame 37. Brackets 77 respectively are fixedly attached to and project rearwardly from the intermediate portions of vertical members 43 of base member 23. Actuating cylinder assemblies 69 pivotally move base member 23 and the leg and arm members about pivot pin 49. An upright cylinder assembly 79 is secured to and extends between mast structure 19 and carriage 21. Actuating cylinder assembly 79 elevatingly move carriage 21, base member 23, and the leg and arm member components. Such structure for mounting cylinder assembly 79 and such mechanism operable for lifting carriage 21 have not been specifically illustrated in the drawings, nor will they be described in detail in the specification, as this is typical and is well-known to those skilled in the art. Typically, a pair of cylinders 31 (only one shown) extend between mast structure 1& and truck body 15. Cylinder base and rod pins 83, 85, extending respectively through apertured brackets 37, 89, securely pivotally mount the cylinders. Actuating cylinder assemblies 81 move mast structure 19, carriage 21, base member 23, and the leg and arm member component about pivot pins 31, and move such mechanism toward and away from truck chassis 13.

In describing the use of mechanism 11, reference may be had to FIG. 1, which illustrates its use in selecting two logs from the far side of a log stack; the mechanism being loaded by urging the logs between leg members 25 and arm members 27. In manipulating mechanism 11 for accomplishing such a log loading operation, the operator of the lift truck may carry out the following simple steps, or proceed as follows: The lift truck is piloted to approach the log stack with mechanism 11 elevatingly disposed as illustrated in FIG. 2. Mast structure 19, and substantially all the mechanism, is pivotally moved forward by actuating cylinder assemblies 81. Base member 23 is tilted forwardly by actuating cylinder assemblies 69, and leg members 25 are projected downwardly. Carriage 21 is lowered by actuating cylinder 79, and the lift truck is moved forward to engage the logs with leg members 25 and member 60. Arm members 27 are actuated by cylinders 63 to urge and hold the logs between the arm and leg members and base member 23. Substantially the reverse of the above steps may then be carried out to lift and transfer the logs to a desired location. In unloading the logs from the lift truck, and in positioning the logs in a desired place, the following steps may be carried out: The operator positions the lift truck, tilts the leg members forwardly, lowers the carriage, opens the arm members, and then raises the carriage and disengages the mechanism from the logs.

The mechanism of the present invention provides means whereby the operator of a lift truck may manipulate and readily sort out desired logs from a log pile. It provides means whereby the operator may readily load or unload the logs by operating the mechanism, without the need of additional workmen on the ground for the loading and unloading tasks. Such a mechanism also provides means for deftly manipulating and accurately placing the logs. In summary, the mechanism of the present invention saves much time and effort in manipulating or sorting out logs, pulpwood, lumber or the like.

Although the present invention has been described and illustrated with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications may be made therein which are within the full intended scope of this invention as hereinafter claimed.

I claim:

In an industrial vehicle including a chassis, a machine for manipulating logs or the like comprising an upright mast structure, means pivotally mounting said mast structure adjacent the lower end thereof from said chassis, a carriage including a frame having a lower horizontally disposed member and two laterally opposed vertically disposed members, means including a plurality of rollers journaled respectively from said vertically disposed members of said carriage frame for securing said carriage from said mast structure and for elevational movement of said carriage, a base part including a lower horizontally disposed member and four vertically disposed members secured to said horizontally disposed member and extending upwardly therefrom and with said four vertically disposed members of said base part being arranged in two pairs of members, a pair of pivot assemblies including bracket means secured respectively to said lower horizontally disposed member of said carriage and said lower horizontally disposed member of said base part, said pair of pivot assemblies including respectively pivot pin means pivotally connecting respectively said bracket means of said carriage and said base part, said base part being pivotally supported from said carriage by said pair of pivot assemblies and movable toward and away from said carriage, a pair of leg members secured to said base part with said leg members including respectively distal end portions extending outwardly and substantially perpendicularly from said lower horizontally disposed member of said base part, a pair of arm members having respectively proximal end portions and distal end portions, means pivotally mounting said pair of arm members from said base part with said proximal end portions thereof being respectively pivotally secured between the two members of each pair of said vertically disposed members of said base part, said pair of arm members additionally including a. cross-member rigidly securing said pair of arm members, said cross-member being wedge-shaped in cross-section and respectively fixedly attached to and interconnecting said distal end portions of said pair of arm members, said cross-member being angled inwardly towards the lower edge thereof from the opposite side edges thereof, said pair of arm members being pivotally movable together toward and away from said pair of leg members; and individual actuating means for operatively moving selectively said mast structure, said carriage, said base part, and said pair of arm members.

References Cited by the Examiner UNITED STATES PATENTS 2,870,925 1/1959 Bernad et .al. 214-147 2,938,595 5/1960 Miller 187-9 2,997,193 8/1961 Dunham 214-654 3,083,853 4/1963 Hastings 214-660 3,124,263 3/1964 Eaves 2l4-654 3,140,002 7/1964 Garrett 214-147 3,164,405 1/1965 Lull 214-654 X 3,165,345 1/1965 Gardner 214-654 X 3,203,566 8/1965 Kampert et al.

FOREIGN PATENTS 1,297,478 5/1962 France.

GERALD M. FORLENZA, Primary Examiner. R. B. JOHNSON, Assistant Examiner. 

